// 2025/8/15
// 计算字符串的编辑距离

#include <iostream>
#include <vector>
using namespace std;

int main() {
    string str1, str2;
    cin >> str1 >> str2;
    int m = str1.size(), n = str2.size();
    vector<vector<int>> dp(m + 1, vector<int>(n + 1));
    for(int i = 0; i <= m; i++)
    {
        dp[i][0] = i;
    }
    for(int j = 0; j <= n; j++)
    {
        dp[0][j] = j;
    }

    for(int i = 1; i <= m; i++)
    {
        for(int j = 1; j <= n; j++)
        {
            dp[i][j] = dp[i - 1][j - 1];
            if(str1[i - 1] != str2[j - 1])
                dp[i][j]++;

            dp[i][j] = min(dp[i][j], min(dp[i - 1][j], dp[i][j - 1]) + 1);
        }
    }
    cout << dp[m][n] << endl;
}
// 64 位输出请用 printf("%lld")